Hi and welcome to HCM. It doesnt sounds like STD but it could be some fungal infection
or molluscum contagiosum
. If you dont experience symptoms such as pain while urinating or in lower abdomen, you shouldnt be worried. This also can be caused by irritation or allergies but may be the result of factors such as hormonal
fluctuations, excessive sweating
or sebaceous cysts.Maybe you noticed clogged sebaceous cysts or sweating glands which are sometimes very expressed and enlarged in normal condition.
Try not wear synthetic underwear as it may cause allergic skin reactions. Tampons, douches etc may cause such allergy
too.Proper hygiene is enough in most cases.
Clean the genital area well and wipe dry. Regular exfoliation of the area may also help prevent clogged sweat glands and inflamed hair follicles.
If this wont be helpful you should visit gynaecologist and do STD testing to rule out some more serious disorders.
WIsh you good health.